An aircraft with folding mechanism, the aircraft including a fuselage, optionally a payload and/or landing gear attached to the fuselage, at least two longitudinal beams attached to the fuselage that preferably extend parallel to each other and parallel to a first aircraft axis, with lifting units attached to each of the longitudinal beams. At least one crossbeam is attached to the fuselage, and preferably extending parallel to a second aircraft axis and at right angles with respect to the longitudinal beams, with lifting units attached to the crossbeam. The longitudinal beams are rotatably attached to the fuselage by at least one respective first pivot joint configured for pivoting the longitudinal beams around a respective first pivot axis to a pivoted position. The crossbeam is rotatably attached to the fuselage, preferably by at least one second pivot joint, for pivoting the crossbeam around a second pivot axis to a pivoted position.

A coaxial rotor system for a rotorcraft includes a mast, a top rotor assembly and a bottom rotor assembly. The top rotor assembly is coupled to the distal end of the mast. The bottom rotor assembly includes a motor configured to provide rotational energy to the mast, thereby rotating the top rotor assembly. The bottom rotor assembly experiences a torque reaction force responsive to the motor rotating the mast such that the top and bottom rotor assemblies counter rotate.

A coaxial rotor system for a rotorcraft includes a mast, a top rotor assembly and a bottom rotor assembly. The top rotor assembly is coupled to the distal end of the mast. The bottom rotor assembly includes a motor configured to provide rotational energy to the mast, thereby rotating the top rotor assembly. The bottom rotor assembly experiences a torque reaction force responsive to the motor rotating the mast such that the top and bottom rotor assemblies counter rotate.

A tilting system for a propeller of an aerial vehicle, may include a propeller provided in front of the opening portion of the housing and configured to be selectively tilted with respect to the housing; a link assembly provided in the internal space of the housing, a first end portion of which is connected to the housing and a second end portion of which is connected to the propeller, and configured to tilt up or tilt down the propeller as the link assembly is extended from the housing or retracted into the housing; and an actuator coupled to the link assembly and configured to provide power for extension or retraction to the link assembly.

A tilting system for a propeller of an aerial vehicle, may include a propeller provided in front of the opening portion of the housing and configured to be selectively tilted with respect to the housing; a link assembly provided in the internal space of the housing, a first end portion of which is connected to the housing and a second end portion of which is connected to the propeller, and configured to tilt up or tilt down the propeller as the link assembly is extended from the housing or retracted into the housing; and an actuator coupled to the link assembly and configured to provide power for extension or retraction to the link assembly.

A duct for a ducted-rotor aircraft includes a hub, a duct ring, and a plurality of stators that extend outward from the hub. The duct ring defines a trailing edge. The duct includes one or more fittings, such as a system of fittings. Each fitting has a body that defines a first attachment interface that is configured to couple to structure of the duct ring and a second attachment interface that is configured to couple to one of the plurality of stators. The first and second attachment interfaces are spaced from each other such that when the fittings are coupled to the duct ring and the plurality of stators, all or substantially all of each of the plurality of stators are located aft of the trailing edge of the duct ring.

A duct for a ducted-rotor aircraft includes a hub, a duct ring, and a plurality of stators that extend outward from the hub. The duct ring defines a trailing edge. The duct includes one or more fittings, such as a system of fittings. Each fitting has a body that defines a first attachment interface that is configured to couple to structure of the duct ring and a second attachment interface that is configured to couple to one of the plurality of stators. The first and second attachment interfaces are spaced from each other such that when the fittings are coupled to the duct ring and the plurality of stators, all or substantially all of each of the plurality of stators are located aft of the trailing edge of the duct ring.

An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a biplane orientation. The aircraft has an airframe including first and second wings with a fuselage extending therebetween. A propulsion assembly is coupled to the fuselage and includes a counter-rotating coaxial rotor system that is tiltable relative to the fuselage to generate a thrust vector. A flight control system is configured to direct the thrust vector. In the VTOL orientation, the first wing is forward of the fuselage, the second wing is aft of the fuselage and the coaxial rotor system is configured to provide thrust in line with a yaw axis of the aircraft. In the biplane orientation, the first wing is below the fuselage, the second wing is above the fuselage and the coaxial rotor system is configured to provide thrust in line with a roll axis of the aircraft.

An aircraft operable to transition between thrust-borne lift in a VTOL orientation and wing-borne lift in a biplane orientation. The aircraft has an airframe including first and second wings with a fuselage extending therebetween. A propulsion assembly is coupled to the fuselage and includes a counter-rotating coaxial rotor system that is tiltable relative to the fuselage to generate a thrust vector. A flight control system is configured to direct the thrust vector. In the VTOL orientation, the first wing is forward of the fuselage, the second wing is aft of the fuselage and the coaxial rotor system is configured to provide thrust in line with a yaw axis of the aircraft. In the biplane orientation, the first wing is below the fuselage, the second wing is above the fuselage and the coaxial rotor system is configured to provide thrust in line with a roll axis of the aircraft.

An aircraft includes an airframe with first and second wings having a fuselage extending therebetween. A propulsion assembly is coupled to the fuselage and includes a counter-rotating coaxial rotor system that is tiltable relative to the fuselage to generate a thrust vector. Tail assemblies are coupled to wingtips of the first and second wings each having an elevon that collectively form a distributed array of elevons. A flight control system is configured to direct the thrust vector of the coaxial rotor system and to control movements of the elevons such that the elevons collectively provide pitch authority and differentially provide roll authority for the aircraft in the biplane orientation. In addition, when the flight control system detects an elevon fault, the flight control system is configured to perform corrective action responsive thereto at a distributed elevon level or at a coordinated distributed elevon and propulsion assembly level.